In this chapter, you learned about various challenges with legacy applications and why it is essential to modernize your legacy application. You learned about different benefits an organization can get by upgrading their application into the latest technology. Application modernization can be a complicated and risky task but is often worth the effort.

The outcome you get from the upgrade is a trade-off for the amount of investment and energy you put into it. Before defining the modernization approach, it's essential to understand your legacy system thoroughly. You learned various assessment attributes of an application in the aspects of technology, architecture, and code. 

After the assessment, the next step is to define the modernization approach. You learned about various modernization approaches, including architecture-driven, system re-engineering, and migration approaches. You also learned about multiple techniques of system modernization, which included the simplest approaches (encapsulation and rehosting) and complex approaches (rearchitecting and redesigning). Cloud can provide a significant value proposition, and you learned about the decision-making approach you need to take for modernization on the cloud.

You focused on the various technical aspects of solution architecture; however, documentation is one of the critical elements of architecture design to keep your system maintainable in the long run. In the next chapter, you will learn about various documentation required for a solution architect to prepare, contribute, and maintain to maximize business value.